August 25, 2010
August 25 - Ixodes holocyclus
This tick, the most commonly found tick along the east coast of Australia, is sometimes called the "Paralysis Tick" due to the unusual symptoms that it can produce in some people. Ixodes holocyclus lives in the wet forests, primarily, and would prefer to feed on Australia's charismatic marsupials (koala, kangaroos, etc), but will readily take its blood meal from humans if it encounters one instead. Toxins in the tick's saliva seem to disrupt neurotransmitters and can produce paralysis in humans, dogs, or other hosts and this can even be fatal if not treated because the paralysis can include muscles for pretty important things like breathing, swallowing and circulation. That said, paralysis from these tick bites is fairly rare, as it is necessary for the tick to remain attached for many days before the toxins will have these kinds of effects, so careful inspection of yourself or pets if in the area can literally be a life-saver. The good news is that there is an antiserum that can be administered if paralysis does set on. The image is a nice example, too, of how drastically different in size a tick will be before and after their blood meals.